Fe–Co hybrid oxides promoted Pd electrocatalysts with enhanced catalytic performance for ethylene glycol oxidation

Effect of Anode Material on Electrochemical Oxidation of Low Molecular Weight Alcohols—A Review

“…These effects take place when doping elements, such as iridium [ 188 ] or gold [ 36 , 57 , 189 , 190 ], induce an upshift in the palladium d-band center and thus result in stronger adsorption of hydroxide ions, which are crucial for complete alcohol oxidation [ 36 , 188 , 190 ]. This mechanism is similar to the electronic effect that takes place after doping with elements, such as copper [ 32 , 184 ], bismuth [ 39 , 154 ], iron [ 33 , 63 , 114 , 154 , 186 ] or ruthenium [ 24 , 39 ]. Instead of increasing the adsorption of hydroxide ions, an electronic effect takes place; in the breaking of inter-carbon bonds, the charge transfer and desorption of CO-based intermediates are improved [ 24 , 39 , 184 ].…”

“…If metal oxides (i.e., RuO 2 , MnO 2 , MoO 2 , and IrO 2 ) are used for platinum embedding, they alter the electrochemical features of the obtained electrode (electronic effect), which changes the adsorption energy of methanol and thus improve the kinetics of the MOR. This effect is caused by changing the conditions of proton and electron transfer by metal oxide hydration [ 34 , 112 , 114 , 115 ].…”

Electrocatalyst Performances in Direct Alcohol Fuel Cells: Defect Engineering Protocols, Electrocatalytic Pathways, Key Parameters for Improvement, and Breakthroughs on the Horizon

“…Some groups have also reported Pd-based bimetallic Pd-Pb, [184] Pd-In 2 O 3 , [185] Pd-Cu, [186][187][188] Pd-Au, [189][190][191] Pd-Ti, [192] Pd-Ag, [193,194] Pd-Ir, [195] Pd-V, [196] NiPdAu, [197] Pd-Fe 2 CoO x , [198] etc. Despite the greater strides and focus on Pd-based electrocatalysts, the research on Pt-based electrocatalysts has not ceased.…”

Nanostructured platinum-free electrocatalysts in alkaline direct alcohol fuel cells: catalyst design, principles and applications

“…To realize the bifunctional mechanism, the majority of the EOR studies in alkaline electrolyte in the last ve years have focused on Pd-based bimetallic catalysts, such as Pd-Ag, [106][107][108][109] Pd-Ni, 51,[110][111][112][113] Pd-Sn, [114][115][116] Pd-Pb, 117 Pb-Tb, 118 Pd-Bi, 119 Pd-In 2 O 3 , 120 Pd-NiO, 90 and Pd-CeO 2 , 90 as well as ternary catalysts, such as Pd-Ir-Ni, 121 Pd-Ru-Sn, 114 FeCo@Fe@Pd, 36 and Pd-Fe 2 CoO x . 122 The underlying mechanisms of the Pd-catalyzed EOR in alkaline media, established from in situ spectroscopic techniques, are intricately linked to factors such as the pH electrolyte, electrode potential, water, and adsorbed acyl and hydroxyl species. Recently, using in situ FTIR spectroelectrochemistry, Fang et al 123 proved that breaking of the C-C bond of ethanol at the Pd electrode is dependent on the pH of the electrolyte; total C-C bond breaking occurs only at pH # 13, while at pH 14, partial oxidation occurs, with acetate being the only oxidation product of the EOR, indicating that the faradic efficiency of the EOR with Pd is lowered at an elevated alkaline pH.…”